Boom assembly for a crane

ABSTRACT

The boom assembly has a boom member and a stock member of box constructions with the stick member pivoted to the boom member adjacent the top of an upright extension provided at the free or forward end of the boom member. The actuating cylinder for the stick member is located within the boom member, and the actuating cylinder for the boom member projects transversely therethrough adjacent its rear end for pivotal connection with the upper wall of the boom member.

United States Patent Grundon [54] BOOM ASSEMBLY FOR A CRANE 51 Oct. 3,1972 Primary Examiner-Gera.ld M. Forlenza Assistant Examiner-George F.Abraham [72] Inventor. John L. Grundon E. 16th &

Howard D12, Des Moines, Iowa Atmmey Rud]ph Lowell 50333 [57] ABSTRACT[22] Filed: Sept. 15, 1970 The boom assembly has a boom member and astock I PP N05 72,333 member of box constructions with the stick memberpivoted to the boom member adjacent the top of an 52 US. Cl. ..214/1470, 214/147 AS upright extension provided at the free or forward end 51Int. Cl ..B66c 1/47 of the boom member- The actuating cylinder for the[58] Field of Search ..214/147, 147 o, 147 AS stick member is located hn he m m m r, and the actuating cylinder for the boom member projects[56] References Cited transversely therethrough adjacent its rear endfor pivotal connection with the upper wall of the boom UNITED STATESPATENTS member.

3,080,988 3/1963 Redman ..2l4/l47 G X 3,330,056 7/1967 Woodside..2l4/l47 G X FOREIGN PATENTS OR APPLICATIONS 2 Claims, 7 DrawingFigures 1,027,453 4/1966 Great Britain ..2l4/ 147 G ilv l. T

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/2 U U H B PATENTEDom 3 1912 saw 1 UF 2 BOOM ASSEMBLY FOR A CRANESUMMARY OF THE INVENTION The boom assembly of this invention is of arigid box construction with the pivoted end of the stick member guidablyreceived within the boom member. The pivoted support of the stick memberat a position above the upper wall of the boom member provides for thelocation of the stick cylinder within the boom member and an actuationof the stick member by an effective movement arm equal to at least thedistance between the longitudinal axis of the boom member and thepivotal connection of the stick member. The stick cylinder is thuseffectively shielded by the boom member against any accidental contactengagement with a load suspended from the free end of the stick member.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a perspective view of therear portion of a truck showing a crane with the boom assembly of thisinvention in assembly relation therewith;

FIG. 2 is a top plan view of the boom member, with parts removed for thepurpose of clarity, showing the assembly therewith of the hydrauliccylinder units for actuating the boom member and an associated stickmember;

FIG. 3 is a longitudinal sectional view of the boom member as seen alongthe line 3 3 in FIG. 2;

FIG. 4 is a detail perspective view showing the connection of the boommember with its actuating hydraulic cylinder unit;

FIG. 5 is an enlarged sectional view taken along the line 5 Sin FIG. 2;

FIG. 6 is a diagrammatic illustration of the assembly shown in FIG. 1showing a log being picked up from a ground supported position; and

FIG. 7 is illustrated similarly to FIG. 6 and shows the log in anelevated loading position.

DETAIL DESCRIPTION OF THE INVENTION Referring to FIG. 1 of the drawing,there is illustrated a truck 10 that includes a main frame 11 on whichis rotatably supported in a usual manner a crane 12 having a base deckor platform 13. Pivotally mounted on the base deck 13 for up and downpivotal movement is the boom assembly 14 of this invention whichincludes a boom member 16 and an associated pivoted extension or stickmember 17. The boom member 16 is actuated by a hydraulic cylinder unit18 that has a cylinder 19 pivoted at one end to the base deck 13 and anassociated piston rod 21 pivotally connected to the boom member 16. Thestick member 17 is pivotally moved relative to the boom member 16 by ahydraulic cylinder unit 22. A hydraulically operated grapple hook 23 forengaging and lifting a log 24 is pendantly supported from the free end26 of the stick member 17. A heeler 27 rigidly secured to the stickmember 17 and projected downwardly therefrom coacts with the grapplehook 23 to hold an engaged log in a horizontally extended position.

The boom member 16 (FIGS. 2 and 3) is of a welded box constructioncomprised of a pair of transversely opposite upright longitudinallyextended side members 28 of a channel shape having upper and lower legs29 and 31, respectively, which project inwardly toward each other. Theupper legs 29 are connected together by a rear plate member 32 and acentral plate 33. In like manner the lower channel legs 31 are connectedtogether by a rear plate member 34 and a central plate member 36.Secured to the forward sections 37 of the side members 28 and formingextensions thereon projected upwardly from the upper channel legs 29 aretriangular shaped plate members 38 that are connectedtogether by a frontconnecting plate 39. Spaced longitudinally of the side channel members28 and extended transversely thereof between the upper and lower legsections 29 and 31, respectively, are upright connecting plates whichinclude what will be referred to as a front mounting plate 42 and a rearmounting plate 43.

It is seen, therefore, that the boom member 16 (FIG. 3) has the bottomside thereof open between the lower plate members 34 and 36 andforwardly of the central plate member 36 at a position below theextension plates 38. The top side of the boom member 16 (FIG. 2) is openat opposite ends of the upper central plate member 33. I

Secured to the rear mounting plate 43 (FIGS. 2 and 3) is a pair ofrearwardly projected pivot connectors 44 which form part of a pivotconnection that pivotally supports the boom member 16 on the base deck13 of the crane assembly 12. Adjacent the upper end of each extensionplate 38 is a transversely extended bearing member 46. These bearingmembers 46 are in alignment transversely of the boom member 16 toreceive a pivot pin 47 for pivotally connecting the rear end of thestick member 17 to the forward end of the boom member 16. It is to benoted that the stick member 17 is pivotally swingable between theextension plates 38 and forward sections 37 of the side channel members28. i

The hydraulic cylinder unit 22 for actuating the stick member 17 islocated between and extended longitudinally of the channel side members28 with its cylinder 48 in an overlying relation with the front portionof the lower central plate 36. The rear end of the cylinder 22 ispivotally connected to the boom member 16 by means including a pivot pin49 extended transversely of the boom member and rotatably supported inbearings 51 (FIGS. 2 and 5) carried in the side members 28 and in a pairof supporting plates 52 that are secured to and project forwardly fromthe front mounting plate 42. As shown in FIGS. 2 and 3, the longitudinalaxis of the cylinder unit 22 and boom member 16 are substantiallycoincident.

The piston rod 21 of the cylinder unit 18 (FIG. 4) extends transverselyof the boom member 16 through the opening formed between the lowerconnecting plate members 34 and 36, and between the side members 28 forprojection through an opening 40 formed in the upper central connectingplate 33. The free end of the rod 21 is received between a pair oftransversely spaced bearing members 45, carried on the plate 33, forpivotal connection therewith by a 'pivot pin 50.

The stick member 17 is of a box. construction and has a pair of ears orlugs 53 (FIG. 1) projected outwardly from its rear side 54 for pivotalconnection at 56 with the free end of a piston rod 57 that isoperatively associated with the cylinder 48. It will be noted that theaxis for the pivot 56 lies substantially in a horizontal plane common tothe longitudinal axis of the hydraulic cylinder 22 so as to provide aneffective moment arm for actuating the stick member 17 equalsubstantially to the distance between the axes of the pivot 47 and thehydraulic cylinder unit 22 when the stick member 17 is normal to theboom member 16 as illustrated in FIG. 6.

With the boom assembly 14 relatively arranged to provide for the grapplehook 23 picking up a ground supported log 24 (FIG. 6) the hydrauliccylinder unit 22 is located entirely within the confines of the boommember 16. The forward or free end section of the boom member 16 thusfunctions as a housing for the cylinder unit 22. On elevation of theboom assembly 14, concurrently with a movement the stick member 17forwardly from the boom member 16, as shown'in FIG. 7 the rear end 58 ofthe log 24 is engaged by the heeler 27 to provide for the log 24 beinghorizontally extended in an elevated position to facilitate unloadingthereof onto a truck or the like (not shown). As is wellknown, thisheeling action takes place by virtue of that portion of the log 24located ahead of the grapple hook 23 being of a longer length andtherefor of greater weight than the rear portion 58 of the log.

in the loading of the log, it is seen that the rear edge 59 of the log24 is closely adjacent to the underside of the boom member 16 so thatduring the manipulation of the log 24 for loading purposes the log end59 is often moved into striking engagement with the underside of theboom member 16. This is due to the fact that the operators attention isdirected primarily to the relative positions of the log 24 and theloading truck. Where the cylinder unit for a stick member is locatedoutwardly from its associated boom member, such cylinder unit on beingstruck by a log is many times damaged beyond repair or has its servicelife appreciably shortened.

By virtue of the boom assembly of this invention, the cylinder unit 22,even when the rod 57 is partially extended forwardly from the front endof the boom member 16 is completely protected against being struck by alog 24 by virtue of its location between and within the verticalconfines of the channel side members 28. This guarding action isaccomplished while maintaining an efficient actuation of the stickmember 17 by its associated cylinder unit 22 due to the pivot support ofthe stick member at 47 adjacent the upper ends of the upright extensions38.

Although the invention has been described with respect to a preferredembodiment thereof, it is to be understood that it is not to be solimited since changes and modifications can be made therein which arewithin the full intended scope of the invention as defined by theappended claims.

Iclaim:

l. A boom assembly for a long handling crane having a self-propelledframe and a turntable rotatably mounted on said frame comprising:

a. a pivoted boom member of a box construction including a pair oftransversely spaced side members joined by top and bottom members, saidboom member being constructed with a forward section open at the top andbottom sides thereof and a rear section,

b. a pair of bearing supports pro ecting upwardly as an extension ofsaid side members adjacent the front end of said forward section,

c. means pivotally supporting said rear section on said turntable for upand down pivotal movement of said forward section,

d. a stick member having one end positioned between and pivotallysupported on said bearing supports at a first pivotal connection forpivotal movement betweensaid side members,

e. a first linearly extendible and retractible power unit for pivotallymoving said stick member relative to said boom member extendedlongitudinally of and between said side members for extension andretraction relative to said front end of the forward section,

f. means pivotally connecting one end of said first power unit with saidstick member at a second pivotal connection, means pivotally connectingthe other end of said power unit with said side members at a thirdpivotal connection, said first, second, and third pivotal connectionsbeing positioned relative to one another and to the side members of theboom such that when the longitudinal axis of the stick member is normalto the longitudinal axis of said boom member with the stick memberextending downwardly with respect to the boom member, the longitudinalaxis of said power unit is located between the upper and lower sides ofthe side members of the boom member,

g. said first power unit being above the lower side of said boom memberfor all moved positions of said first power unit, whereby said powerunit is protected from underneath by said side members,

h. a second linearly extendible and retractible power unit extendedbetween and pivotally connected to said turntable and the rear sectionof said boom member, and

i. a power actuated log engaging unit movably suspended from the otherend of said stick member.

2. The boom assembly for a log handling crane according to claim 1,wherein:

a. said stick member is movable in the open bottom side of said frontsection on movement rearwardly from the position thereof normal to saidboom member.

1. A boom assembly for a long handling crane having a selfpropelledframe and a turntable rotatably mounted on said frame comprising: a. apivoted boom member of a box construction including a pair oftransversely spaced side members joined by top and bottom members, saidboom member being constructed with a forward section open at the top andbottom sides thereof and a rear section, b. a pair of bearing supportsprojecting upwardly as an extension of said side members adjacent thefront end of said forward section, c. means pivotally supporting saidrear section on said turntable for up and down pivotal movement of saidforward section, d. a stick member having one end positioned between andpivotally supported on said bearing supports at a first pivotalconnection for pivotal movement between said side members, e. a firstlinearly extendible and retractible power unit for pivotally moving saidstick member relative to said boom member extended longitudinally of andbetween said side members for extension and retraction relative to saidfront end of the forward section, f. means pivotally connecting one endof said first power unit with said stick member at a second pivotalconnection, means pivotally connecting the other end of said power unitwith said side members at a third pivotal connection, said first,second, and third pivotal connections being positioned relative to oneanother and to the side members of the boom such that when thelongitudinal axis of the stick member is normal to the longitudinal axisof said boom member with the stick member extending downwardly withrespect to the boom member, the longitudinal axis of said power unit islocated between the upper and lower sides of the side members of theboom member, g. said first power unit being above the lower side of saidboom member for all moved positions of said first power unit, wherebysaid power unit is protected from underneath by said side members, h. asecond linearly extendible and retractible power unit extended betweenand pivotally connected to said turntable and the rear section of saidboom member, and i. a power actuated log engaging unit movably suspendedfrom the other end of said stick member.
 2. The boom assembly for a loghandling crane according to claim 1, wherein: a. said stick member ismovable in the open bottom side of said front section on movementrearwardly from the position thereof normal to said boom member.